A clinical trial of a new expectorant drug (Na 274).
D000336:Aerosols / Q000627:therapeutic use; D001991:Bronchitis / Q000188:drug therapy*; D002986:Clinical Trials as Topic; D005100:Expectorants / Q000008:administration & dosage*; D006801:Humans; D010919:Placebos; D013183:Sputum
D000336:Aerosols; D005100:Expectorants; D010919:Placebos